The present invention relates to a device for the collection of folded printed sheets.
Such a device is known from, for example, DE-OS 36 16 566 and corresponding U.S. Pat. 4,735,406. This device has three saddle-type supports disposed parallel to a common axis of rotation and rotating about said axis. Disposed in series in the direction of the axis of rotation are two feeders for placing printed sheets on the supports and a stapler for stapling together the printed sheets lying on top of one another. The printed sheets thus collated and stapled slide onto a conveyor belt to be conveyed away. For each support provision is made for an endless rotary chain with carriers, which act upon the printed sheets placed on the supports and convey them in the course of a revolution of the supports about the common axis of rotation from one feeder to the next, or to the stapler. Provision is made on either side of each support for guide plates which prevent the printed sheets from spreading out. In order to prevent the printed sheets from falling off the supports while they are being passed through under the axis of rotation, provision is made for a half cylindrical surface on which the printed sheets slide with their fold during the lower half of the rotary movement. Here the printed sheets can be damaged, in particular in the region of their fold. Since a gap must be present between the half cylindrical surface and the carriers, it is also possible for the printed sheets to pass out of reach of the carriers, so that they are no longer conveyed along and are damaged. Furthermore, the placing of the printed sheets on the supports gives rise to problems, since with continuously rotating supports the printed sheets have to be inserted into the gap between the supports and the guide plates.
Another device for the collection of folded printed sheets is known from EP-OS 00 95 603 or the corresponding U.S. Pat. No. 4,489,930. It has supports disposed like the rungs of a ladder on two parallel-rotating conveyor chains. At the beginning and end of the conveying stretch the conveyor chains are conveyed around deflection rollers. Printed sheets are placed astride the supports of the upper track by means of feed conveyors, and the printed sheets thus collected are lifted from the supports at the end of the conveying stretch and conveyed away.
It is a primary object of the present invention to produce a device for collecting folded printed sheets which is simple in design and permits reliable holding of the printed sheets on the supports, and thus avoids damage to the printed sheets.